HDAC1, a novel marker for benign teratomas.

Histone deacetylases (HDACs) are non-redundant chromatin-modifying enzymes that are critical cellular regulators and are often overexpressed in cancers. Targeting them by HDAC inhibitors (HDACis) can induce growth arrest, differentiation or apoptosis, making HDACi agents promising anti-cancer drugs, and these are currently being tested in clinical trials. Specific roles of the individual HDAC isoforms are only poorly understood. In this issue of The EMBO Journal, the group of Christian Seiser publishes an unexpected and novel functional role for HDAC1 in tumourigenesis that is distinct from the role of HDAC2. Using an experimental teratoma model to study the role of HDAC1 in tumour formation, they show that loss of HDAC1 is linked to enhanced tumour malignancy; this is contrary to previous reports linking HDAC1 to unrestricted tumour growth. Correlating with this, they suggest that the presence of HDAC1 could provide a biomarker for benign teratomas.